In recent years, various studies of cytokines have been conducted.
For example, it has been disclosed that the blood level of interleukin in a patient suffering from inflammatory autoimmune disease is higher than that in a healthy human and the metabolic function of a cytochrome P450 in the patient is lower than that in a healthy human; and the metabolic function of CYP3A4 is reduced due to cytokines secreted into blood during inflammation, which makes it difficult to excrete drugs and results in serious side effects (Non Patent Literature 1). In a case where a pharmaceutical (D1) which undergoes the metabolism of the cytochrome P450 is administered to such a patient, a smaller dose of the drug than that for a healthy human is administered to the patient in anticipation of reduction in the metabolic function of the patient. When a drug (D2) (for example, a molecularly-targeted drug), which interacts with a cytokine and blocks interleukin receptors, is used together for the patient, the reduced metabolic function of the cytochrome P450 is restored and the metabolism of the pharmaceutical (D1) is promoted. As a result, according to a clinical study, the action of the pharmaceutical (D1) is attenuated (Non Patent Literature 2). Under such circumstances, the study of the interaction between the drug, such as molecularly-targeted drug, and the pharmaceutical, which undergoes the metabolism of the cytochrome P450, through cytokines has attracted attention.
An example of such techniques is animal testing. However, animal testing has a problem that a reaction in a living organism cannot be correctly predicted due to a species difference between humans and animals (Non Patent Literature 3). Additionally, an in vivo test, such as animal testing, provides a lower throughput performance than that of an in vivo system. Therefore, there is a problem that animal testing is not suitable for drug screening to evaluate a large number of compounds at the same time.
Under such circumstances, there has been a demand for an evaluation method using an in vivo test which can correctly predict a reaction in a living organism. Further, cytokines typified by interleukin have attracted attention as a drug discovery target. In recent years, there is a demand for an in vivo system for evaluating an interaction between drugs and cytokines.